randyjawa 

This is a pretty good question, actually.

I used to ride 54cm seat tube, but these days I ride a 56cm. As I got older, I found it increasingly difficult to get into and maintain a road bicycle crouch while riding. With this in mind, I tried larger frames and found the comfort factor to improve considerably.

So, think about your comfort and how it will impact your enjoyment. For my money, I would go slightly bigger, but that is because I am old and liking relaxed riding positions more than I used to.

Also, two Italian bikes means little to me. I would need to know what makes, conditions, components fitted and lots more. Size is, indeed, an important consideration but so are the other things.